Bihar, an Indian state located in seismic zones III, IV, and V, has experienced severe earthquakes in the past. Due to the presence of alluvium soil deposits over the bedrock in the Bihar region, seismic waves near the ground surface can amplify and cause catastrophic damage to existing structures. Therefore, to ensure the safety of the structures, it is imperative to assess the amplification level of seismic waves near the surface. This study presents a new empirical correlation for the site classes C, D, and E of the Bihar region, which estimates the spectral acceleration (Sa) at the required time period. These site classes of the Bihar region refer to the classification of soil and geological conditions based on their behaviour during seismic events, specifically their impact on seismic wave amplification, ground shaking, and overall earthquake hazard, as per NEHRP classification. The results of this investigation can be applied to enhance the seismic design of structures and, hence, mitigate the seismic risk. Moreover, the developed empirical correlation for Sa can be used to estimate the design spectrum acceleration at the surface level for site classes C, D, and E of the Bihar region.

This study investigates the damping behavior of olive trees under trunk shaking by assessing transmitted acceleration and logarithmic decrement in the soil and tree, as well as the actual shaking, damping, and elastic powers within the tree. The trunk shaker was operated at five attachment heights: 0.4, 0.5, 0.6, 0.7, and 0.8 m. Results revealed that the peak elastic power of 8.8 kW occurred at 0.8 m, after which elasticity declined, indicating that the tree reaches its maximum elastic capacity before inertia dominates. The transmission of acceleration to the root-soil system is influenced by attachment height and trunk diameter, with larger diameters and lower attachment points reducing transmitted acceleration. The highest transmitted acceleration of 30.7 ms- 2 was measured at 0.8 m. Along the x-axis, acceleration progressively increases from the base to the branches, while the y-axis is mostly absorbed by the trunk. Additionally, the logarithmic decrement decreases with distance from the shaker, reflecting greater damping in the trunk compared to the branches. These findings suggest that optimizing attachment height during mechanical harvesting can enhance energy efficiency and minimize damage by improving elastic responses and managing acceleration and damping dynamics.

This paper analyses liquefaction potential in a high seismic region in Bengkulu City, Indonesia. The liquefaction hazard map, derived from the liquefaction potential index using site investigation data and geophysical surveys, is presented. The study begins with collecting site investigation data and measuring geophysical parameters. Peak ground acceleration and potential seismic damage are estimated. Liquefaction potential analysis is based on site investigation data and maximum estimated peak ground acceleration. The integrated map represents the depth-weighted analysis, and the factor of safety, also known as the liquefaction potential index, is discussed. Results indicate the predominance of sandy soils in the study area, prone to liquefaction. Coastal and river channel areas, characterised by loose sandy soils, exhibit high liquefaction potential. The study area is also expected to experience strong motion, potentially reaching intensity level IX on the Modified Mercalli Intensity scale, indicating liquefaction susceptibility during strong earthquakes. Overall, the study results offer recommendations for local government spatial planning development.

The anchor is commonly applied to enhance the seismic stability of a slope. Presently, the seismic permanent displacement of slope is widely estimated with a constant yield acceleration based on Newmark sliding block method, which is not a realistic scenario. Besides, the soil slope is mostly inhomogeneous and anisotropic, where a circular slip surface is not quite suitable for slope stability analysis. To overcome the shortcomings of estimation method of earthquake-induced displacement, a point-to-point strategy is applied to generate the instant discrete failure mechanism of inhomogeneous and anisotropic anchored slope to determine the time-dependent yield acceleration by limit analysis. The recursive formulas of slope and anchor parameters versus seismic displacement at tiny time interval are established to predict the dynamic behavior of slope. The seismic displacement at tiny time interval is estimated by Newmark sliding block method, and the total earthquakeinduced displacement is subsequently determined. The anchor axial force increases significantly during seismic excitation, which causes a time-dependent characteristic of yield acceleration. Moreover, the effect of inhomogeneity and anisotropy is investigated. The slope becomes more vulnerable to earthquake while the inhomogeneity of unit weight is considered. An increment in inhomogeneous factor or a decrement in anisotropic factor of friction angle or cohesion causes the stability of anchored slope to increase.

Past seismic events have shown that caisson quay walls are susceptible to severe damage during earthquakes, underscoring the importance of assessing their seismic behavior. However, very limited studies have been conducted on the soil-structure-water interaction of the caisson-ground system during earthquakes. This study will investigate the seismic response and failure mechanism of a caisson through a centrifuge shake-table test. Specifically, the seismic response results of the backfill, the caisson, and the subsoil are discussed; an acceleration integration method for identifying permanent displacement to estimate the backfill deformation is proposed; and a phase analysis of the seismic response of the caisson-ground system is conducted. It is found that the liquefaction of the backfill results in a substantial increase in the dynamic earth pressure behind the caisson. The failure mode of the caisson is lateral movement accompanied by slight tilting and continuous rocking vibrations. The proposed acceleration integration method can effectively estimate the deformation and lateral spreading of backfill. Phase analysis results reveal the relationship between the failure of the caisson-ground system and seismic action.

Bedding parallel stepped rock slopes exist widely in nature and are used in slope engineering. They are characterized by complex topography and geological structure and are vulnerable to shattering under strong earthquakes. However, no previous studies have assessed the mechanisms underlying seismic failure in rock slopes. In this study, large-scale shaking table tests and numerical simulations were conducted to delineate the seismic failure mechanism in terms of acceleration, displacement, and earth pressure responses combined with shattering failure phenomena. The results reveal that acceleration response mutations usually occur within weak interlayers owing to their inferior performance, and these mutations may transform into potential sliding surfaces, thereby intensifying the nonlinear seismic response characteristics. Cumulative permanent displacements at the internal corners of the berms can induce quasi-rigid displacements at the external corners, leading to greater permanent displacements at the internal corners. Therefore, the internal corners are identified as the most susceptible parts of the slope. In addition, the concept of baseline offset was utilized to explain the mechanism of earth pressure responses, and the result indicates that residual earth pressures at the internal corners play a dominant role in causing deformation or shattering damage. Four evolutionary deformation phases characterize the processes of seismic responses and shattering failure of the bedding parallel stepped rock slope, i.e. the formation of tensile cracks at the internal corners of the berm, expansion of tensile cracks and bedding surface dislocation, development of vertical tensile cracks at the rear edge, and rock mass slipping leading to slope instability. Overall, this study provides a scientific basis for the seismic design of engineering slopes and offers valuable insights for further studies on preventing seismic disasters in bedding parallel stepped rock slopes. (c) 2025 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/ 4.0/).

Early earthquakes often trigger landfill slope failures and damage to cover and liner systems, resulting in gas leakage, environmental contamination, and significant risks to landfill safety. Accurately assessing the static and dynamic characteristics of mechanically biologically treated (MBT) waste is crucial. Centrifuge shaking table tests offer a robust method to address the limitations of conventional shaking table tests by effectively simulating the static and dynamic stress-strain fields of prototype soils, fulfilling the requirements for comprehensive static and dynamic analysis. Accordingly, this study conducted experimental research on MBT waste using a centrifuge shaking table. Key findings are as follows: (1) The Poisson's ratio of MBT waste is 0.483, and its small-strain shear modulus increases with depth, with a derived equation representing the relationship between small- strain shear modulus and depth. (2) MBT waste demonstrated a significant dynamic amplification effect, with an amplification factor ranging from 1.122 to 1.332. (3) The equivalent shear modulus of MBT waste decreases with increasing strain but increases with depth, with a surface equation established between the equivalent shear modulus, strain, and depth. (4) The equivalent damping ratio of MBT waste varies with strain and depth, and a surface equation was established to capture this relationship. (5) A comparison of the normalized equivalent shear modulus and equivalent damping ratio between MBT waste and municipal solid waste (MSW) shows that both parameters are higher in MBT waste than in MSW. These findings provide valuable insights for seismic stability analysis of MBT landfills.

To adapt to higher and steeper slope environments, this paper proposes a new type of support structure called an anchored frame pile. The study designed and conducted a series of shaking table tests with three-way loading. The acceleration field of the slope, bedrock and overburden layer vibration variability, Fourier spectra, pile dynamic earth pressure, anchor cable force, and damage were analyzed in detail. The results indicate that the overall effectiveness of anchored frame piles for slope reinforcement is superior, and the synergistic impact of front and back piles is evident. Anchor cables effectively reduce the variability of bedrock and overburden layer vibrations. A zone of acceleration concentration always exists at the shoulder of a slope under seismic action. The dominant Fourier frequency in the Y direction of the slope is 11.7687 Hz under Wolong seismic, and the high-frequency vibrations of the upper overburden layer are significantly stronger than those of the bedrock. Slopes under 0.4 g earthquakes first form cracks at the top and then expand downward through them. Under seismic action, the peak dynamic earth pressure in front of the front pile occurs near the bottom of the pile, and the dynamic earth pressure behind the pile occurs near the slip surface. The peak dynamic earth pressure of the back pile occurs at the top of the bedrock. The slope damage is significant at 0.6 g. At this point, the peak dynamic soil pressure at the top of the front pile measures 9.5 kPa, while the peak dynamic soil pressure at the bottom reaches 24.3 kPa. Below the sliding surface of the front pile and on top of the bedrock of the back pile are the critical areas for prevention and control. Elevating the prestressing of the anchor cables will help enhance the synergy between the anchor cables and the piles. Simultaneously, it will reduce the variability of vibration in the bedrock and overburden, thereby improving the stability of the slopes.

An earthquake event with a moment magnitude of 7.7 took place in Pazarc & imath;k (Kahramanmara & scedil;, T & uuml;rkiye) on February 6, 2023. Approximately 9 hours after this event, another powerful earthquake event in Elbistan (Kahramanmara & scedil;) with a moment magnitude of 7.6 occurred. This study reports the level of devastation in Kahramanmara & scedil;, Hatay, and Ad & imath;yaman cities of T & uuml;rkiye that were heavily affected. Mainly, the characteristics of the recorded input motions at the affected areas and their spectral accelerations at different sites (possessing different soil classes) along with the design values are evaluated. Moreover, soft-weak story failures and pancake collapses of buildings are discussed together with strong column-weak beam philosophy. The influence of site effect on the input motions and, therefore, on the structural damages is highlighted, too.

Quantifying the progressive failure of infrastructures under seismic excitation is crucial for accurate risk evaluation. Such analyses often necessitate detailed structural evaluations using numerous ground motion records across a range of seismic intensities. This study proposes intensifying artificial acceleration (IAA) as a novel method for approximating the seismic response of structural systems. The performance of IAA is evaluated in comparison with traditional single-record incremental dynamic analysis (IDA), employing a benchmark geostructure problem that incorporates soil/rock-structure interaction. This research assesses the efficacy and precision of IAA for nonlinear systems with and without wave propagation in the foundation. Wave deconvolution is applied to both IAA and IDA, and a damage index is calculated to quantify crack extension. Serving as a proof of concept, the results highlight a promising alignment between IAA and IDA outcomes, with IAA offering significant reductions in computational demand. The paper concludes with a conceptual framework for integrating ground motion-compatible IAAs into streamlined risk assessment processes.